In performing laser surgery on the eye, and in particular in performing laser surgery on the lens of the eye, such as for the purpose of performing a laser assisted capsulotomy, an interface device is needed that touches the anterior surface of the eye and docks with the laser device that is being used to perform the surgery. Such laser devices and systems are disclosed, for example in published applications US 2007/173794 A1, US 2007/173795 A1, US2007/185475 A1, WO 2007/084694 A2, WO 2007/084627 A2, the disclosures of which are incorporated herein by reference.
A particular problem that may occur with such interface devices arises because the laser beam must pass through the interface device which has a different index of refraction than the components of the eye that the laser beam must also pass through to reach the lens. This difference in the index of refraction creates difficulties in accurately placing the laser beam at a particular point in the lens of the eye or at particular points in other structures within the eye. Previously, this problem has been addressed by the use of complex mathematical algorithms that attempted to compensate for the difference in the index of refraction. Moreover, this problem is even further increased when the surfaces of the interface device through which the laser beam must travel are not flat.